JPH09214991A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further miniaturize an image pickup device, in which a light receiving plane can be extended and the number of picture elements can be increased, in a more simplified configuration. SOLUTION: An optical path dividing optical element 20, in which light flux transmitted through an image pickup lens is reflected on a reflection plane and divided into plural pieces of light flux and the different parts of an entire subject are formed from the respective pieces of divided light flux, is formed from four triangular prisms 21, 22, 23 and 24. Then, the slopes of respective triangular prisms 21-24 are defined as reflection planes 21a, 22a, 23a and 24a, the divided light flux reflected on the respective reflection planes 21a-24a is received by CCD imaging devices 31, 32, 33 and 34 and images at the different parts of the entire subject are picked up.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an image pickup apparatus using a plurality of image pickup elements.

[0002]

2. Description of the Related Art Recently, an electronic still camera has been developed in which an image of an object is picked up by a CCD image pickup device instead of a silver salt film and recorded as an electric signal. For example, there is one in which a lens and a body of a single-lens reflex camera for a silver salt film are diverted and a CCD image pickup element is arranged at a film surface position (press plate position).

However, the light receiving surface size (effective screen size) of a general CCD image pickup device is only 6.6 × 8.8 mm for a so-called 2/3 inch type CCD image pickup device. On the other hand, the screen size of a Leica single-lens reflex camera (hereinafter referred to as “Leica version camera”) that uses a general silver salt film is 24 × 36 mm. Therefore, if the film of the Leica camera is simply replaced by a 2 / 3-inch CCD image sensor, the screen size for an electronic still camera is about 1/4. In other words, if the interchangeable lens of the Leica version camera is used as it is for an electronic still video camera, a lens with the same focal length but with a focal length of about 1/4 of the angle of view must be used. For example, if an interchangeable lens with a focal length of 50 mm of a Leica camera is used as it is, it will correspond to a focal length of 200 mm with a Leica camera when using an electronic still video camera. Normally, the focal length of interchangeable lenses for Leica cameras is generally 20 to 300 mm, but these interchangeable lenses are equivalent to 80 to 1200 mm when used with electronic still cameras, which means that the so-called wide-angle to standard-angle lenses can be used. I couldn't shoot.

Moreover, the inexpensive CCD image pickup device which is now popular has a small number of pixels per unit area, that is, the resolution is lower than that of the silver salt film. Therefore, the subtle texture expressed by the silver halide film cannot be expressed by the CCD image pickup device, and it is difficult to obtain a beautiful work. A high resolution CCD image pickup device having a large number of pixels per unit area is very expensive, and an electronic still camera using the high resolution CCD image pickup device is very expensive.

[0005] In a CCD image pickup device, a substrate portion that cannot receive light generally exists around a light receiving surface. Therefore, when the CCD image pickup devices are arranged on the same plane, the substrate portions adjacent to each other mechanically interfere with each other, so that the light receiving surfaces cannot be disposed adjacent to each other.

As a means for solving such a problem, there is known one in which an image pickup range is divided into a plurality of areas and each divided image pickup area is picked up by a low resolution CCD image pickup device. For example, a reflector having a plurality of reflecting surfaces is arranged in the optical path of the photographing optical system, the optical paths are divided, and a subject light flux in each optical path is received by a CCD image pickup element arranged on the image forming surface, and an image is taken. Then, an image captured by each CCD image sensor is combined to form one screen.

As the optical path dividing means, a roof-shaped reflector is known for dividing the optical path into two or more, and a polygonal pyramid-shaped reflector is known for dividing the optical path into three or more. 191678, JP-A-4-114573, JP-A-4-145
No. 74, JP-A No. 4-244791).

However, in the conventional optical path splitting means, since all of the light beams are split by the reflecting surface, if the number of splits is increased, the polygonal pyramidal reflector has a peculiar shape, which makes it difficult to manufacture. is there. Further, in the conventional optical path splitting means, since each CCD image pickup device is fixed in a state of being rotated from the vertical and horizontal directions about the optical axis, there is a problem that the entire image pickup device becomes large. Further, in the conventional optical path splitting means, since each reflecting surface is in contact with the adjacent reflecting surface, it is difficult to make fine adjustment such as angle adjustment and position adjustment for each reflecting surface unit.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and it is an object of the present invention to reduce the size of an image pickup device capable of increasing the light receiving area and the number of pixels with a simpler structure. And

[0010]

SUMMARY OF THE INVENTION In order to achieve this object, the invention according to claim 1 reflects a light flux transmitted through an image pickup lens by a reflecting surface and divides the light flux into a plurality of light fluxes, and each divided light flux forms a different portion of a subject image. And a plurality of image pickup elements for receiving each of the divided luminous fluxes, and the reflecting surface of the optical path-dividing optical element is formed by each inclined surface of the plurality of triangular prisms. . The invention according to claim 2 is characterized in that the optical path splitting optical element has four reflecting surfaces, and each reflecting surface is formed by four inclined surfaces of right-angled isosceles triangular prisms. The invention according to claim 4 is characterized in that each triangular prism is arranged so as to reflect the subject light flux in a direction orthogonal to the optical axis of the photographing lens and in the horizontal or vertical direction. According to a seventh aspect of the present invention, an optical path splitting optical element that reflects a light flux that has passed through an imaging lens on a reflecting surface and splits the light flux into four light fluxes, and forms different portions of a subject image by each split light flux; And four image pickup elements for receiving the respective luminous fluxes,
It is characterized in that the reflecting surface of the optical path splitting optical element is formed by four flat plate-shaped mirrors. The invention according to claim 8 is characterized in that each of the mirrors according to claim 7 is provided with an angle adjusting mechanism. According to a tenth aspect of the present invention, the image pickup apparatus according to the seventh aspect is characterized in that the mirror and the image pickup element are fixed to the same frame. The invention described in claim 11 is the image pickup apparatus according to claim 7, wherein the mirror is a half mirror, and a subject image transmitted through the half mirror can be observed as an erect real image in the rear part of the half mirror. It is characterized by having a finder optical system.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing configurations of an optical path splitting optical element and a CCD image pickup element according to an embodiment of the present invention. In this embodiment, the subject light flux forming the entire screen 10 is divided by the optical path dividing optical element 20 into the subject light fluxes forming the four divided screens 11, 12, 13, and 14, and the divided screens 11, 12, 13 are formed. , 14, four CCD image sensors 31, 32, which are arranged apart from each other.
The configuration is such that images are captured by 33 and 34. That is, the divided light fluxes forming the images on the CCD image pickup devices 31 to 34 are divided into the first, second, third, and fourth divided screens 11 and 12 obtained by dividing the entire screen 10 into four, unless the optical path dividing optical element 20 is present. , 13, 1
The respective subject images are formed on the surface 4, and one subject image is formed as a whole. Object images corresponding to the divided screens 11 to 14 are formed on the effective light receiving surfaces of the CCD image pickup devices 31 to 34, and are imaged by the CCD image pickup devices 31 to 34.
The divided subject images picked up by the CCD image pickup devices 31 to 34 are combined into one subject image corresponding to the entire screen 10 by image processing means (not shown).

In this optical path splitting optical element 20, four reflecting surfaces 21a, 22a, 23a and 24a are formed by the inclined surfaces of four triangular prisms 21, 22, 23 and 24, and four CCs are provided.
Each of the light receiving surfaces of the D image pickup elements 31, 32, 33, and 34 is characterized by being arranged orthogonal to the optical axis of the photographing lens and in the horizontal or vertical direction of the camera. These triangular prisms 21, 22, 23, and 24 are isosceles right-angled prisms, and have inclined surfaces as reflecting surfaces. The triangular prisms 21 to 24 are integrally formed on the common substrate 20A, or they are integrated by bonding.

The subject light flux that has passed through the taking lens L is reflected by the first to fourth reflecting surfaces 21, 22, 23 and 24, and the first to fourth CCD image pickup elements 31, 32, 33 and 3 respectively.
It is incident on the light receiving surface of No. 4. That is, the subject light fluxes forming the first, second, third, fourth split screens 11, 12, 13, and 14 are respectively reflected by the first, second, third, and fourth CCD image pickup elements 31, respectively.
Light is received at 32, 33, and 34. Therefore, the subject image 11i corresponding to the first split screen 11 is captured by the first CCD image sensor 31, and the subject image 12i corresponding to the second split screen 12 is captured by the second CCD image sensor 32. Third
The subject image 13i corresponding to the divided screen 13 of the third CC
The D image sensor 33 captures an image, and the subject image 14i corresponding to the fourth split screen 14 is captured by the fourth CCD image sensor 34.

The subject images 11i to 14i imaged by the CCD image pickup devices 31 to 34 are usually processed as an electric digital signal (digital video signal) by an image processing circuit and combined into one seamless image data. To be done.
The combined image data is recorded on a recording medium and used as display data on a display or print data for a printer.

As described above, the optical path splitting optical element 20 according to the first embodiment of the present invention is composed of four triangular prisms, and the reflecting surfaces 21a to 24a are formed by the inclined surfaces of the respective triangular prisms. Yes, it can be manufactured with high precision, and the cost is low. Further, according to the first embodiment, the facing CCD image pickup devices 31 and 33 and the CCD image pickup devices 32 and 34 are arranged in parallel and face each other, and the respective CCD image pickup devices 31 to 34 are arranged on the respective sides of the entire screen. Since they can be arranged in parallel, they can be easily configured and adjusted, and the imaging device as a whole can be easily downsized.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, the optical path splitting optical element 202 is composed of a flat plate mirror, that is, the reflecting surfaces 21a to 24a formed by the inclined surface of the triangular prism in the first embodiment are flat mirrors. 212, 222,
232, 242, and each mirror 21
The feature is that the angle adjustment of 2, 222, 232, and 242 is possible.

The subject light flux that has passed through the taking lens (not shown) is reflected by the first, second, third and fourth mirrors 212, 222 and 23.
It is reflected at 2, 242 and divided into the first, second, and
3, 4 CCD image pickup elements 312, 322, 332, 342
On the light receiving surface of the split screen 1 according to the first embodiment.
Subject images 11i, 12 corresponding to 1, 12, 13, 14
i, 13i, 14i are formed. CCD image sensor 312
The structure and operation of ˜342 are the same as those of the CC of the first embodiment.
This is the same as the D image pickup elements 31 to 34.

In this embodiment, each of the mirrors 212 to 24 is used.
2 is supported by an eccentric screw so that the angle can be adjusted.
An example of the support structure will be described with reference to FIG.
FIG. 4 shows a support structure for the first mirror 212.
Both edges of the first mirror 212 parallel to the horizontal direction are supported by eccentric screws 411 and 412 extending in the horizontal direction. The eccentric screws 411 and 412 have large-diameter screw portions 421,
422, and small-diameter support shafts 431 and 432 project from the eccentric positions of the tip surfaces of the screw portions 421 and 422. The large-diameter screw portions 421 and 422 are screwed and supported in screw holes of a frame (not shown), and the first mirror 212 is
The back surface is in contact with and supported by the support shafts 431 and 432.

In the figure, one eccentric screw 411 is located at a position where the support shaft 431 is closest to the first mirror 212.
In other words, it is at the highest position, and the other eccentric screw 412 is
The support shaft 432 is at the position farthest from the first mirror 212, that is, at the lowest position. If, for example, one of the eccentric screws 411 is rotated from this state, the first mirror 21
For No. 2, the eccentric screw 411 side is lowered. Therefore, the light beam that is incident on the first mirror 212 and reflected in the B0 direction is B1
It will be reflected in the direction. On the contrary, the other eccentric screw 41
2 is rotated, the first mirror 212 moves the eccentric screw 412.
Side rises. Therefore, the light ray that has entered the first mirror 212 and is reflected in the B0 direction comes to be reflected in the B2 direction.

As described above, the eccentric screws 411 and 412 are rotated to adjust the inclination of the first mirror 212. If this adjustment is performed during manufacturing, after the adjustment, the eccentric screw 411,
The 412 can be fixed with an adhesive or the like so as not to rotate, or the first mirror 212 can be fixed to a support frame (not shown) with an adhesive or the like.

Although only the structure of the first mirror 212 is shown in the drawings, this structure is used for all the other mirrors 222 to 222.
242 can be applied. Further, in the present embodiment, only the angle adjustment about one axis is possible, but it is also possible to adjust the angle around two axes or three axes orthogonal to each other. The angle adjusting mechanism is provided on the back side of each of the mirrors 212 to 242.

As described above, in the second embodiment, since the respective reflecting surfaces of the optical path splitting optical element 202 are composed of the independent mirrors 212 to 214, the respective mirrors 212 to 242 are independently positioned. , The angle can be adjusted.

In the second embodiment, the optical path splitting optical element 2 is used.
02 and the CCD image pickup devices 312 to 314 were independently separated. FIG. 5 shows a third embodiment in which the optical path splitting element and the CCD image pickup element are fixed in the same frame. In FIG. 5, the first mirror 213 and the first CC are shown.
Only the D image sensor 313 is shown. The first mirror 213 and the first CCD image sensor 313 are fixed to the frame 511. The frame 511 is made of synthetic resin, die cast, or the like, and its surface is subjected to antireflection processing. Similarly, the second mirror 223 and the second CCD
The image sensor is fixed to the frame 512, the third mirror and the third CCD image sensor are fixed to the frame, and the fourth mirror 2
The fourth CCD image sensor 43 and the fourth CCD image sensor are fixed to the frame 514.

Although not shown in detail, each mirror and the corresponding CCD image pickup device may be fixed to a frame as shown in FIG. 5 and the frames may be joined together.

As described above, in the third embodiment, the optical path splitting optical element and the CCD image pickup element are fixed to the same frame, so that the manufacturing is facilitated and stable and high accuracy is facilitated. Moreover, the adjustment is easy.

FIG. 6 shows a fourth embodiment. In the first to third embodiments, all the subject light flux is reflected by the reflecting surface, but in the fourth embodiment, the mirror is configured by a half mirror and the subject light flux is transmitted through the half mirror. In this embodiment, an optical finder is added for observing as an erect real image through the erecting optical system. In the fourth embodiment, the half mirrors 214 to 244 and the CCD image pickup devices 314 to 344 of the optical path splitting optical element 204 can be arranged similarly to those in the second embodiment.

A part of the subject light flux that has passed through the zoom objective optical systems L14 and L24 passes through the optical path splitting optical element 204, passes through the focusing plate L3, the condenser lens L4, the erecting optical system L5, and the eyepiece optical system L6. Shoot out from. The observer can observe the subject image formed on or before and after the focusing plate L6 as an erect real image via the eyepiece optical system L6 and the erecting optical system L5. That is, the photographer can take an image while observing the shooting range, structure, and focus state.

As described above, the illustrated embodiment shows an example in which the image pickup screen is divided into four, but the present invention does not limit the number of divisions. Although the CCD image pickup device is shown as the image pickup device, other solid-state image pickup devices may be used.

[0029]

As is apparent from the above description, in the invention described in claim 1, the optical path splitting optical element for splitting the light flux by reflection is composed of a plurality of triangular prisms, and the slopes thereof are the reflecting surfaces. The optical path splitting optical element can be formed with a simple structure, and a high-definition, high-quality imaging device can be easily manufactured. According to the invention described in claim 4, since each triangular prism is arranged so as to reflect the subject light flux in a direction orthogonal to the optical axis of the photographing lens and in the horizontal or vertical direction, the image pickup element is also arranged with respect to the photographing axis. The optical path splitting optical element and the image pickup element can be easily positioned and the space can be easily saved because they are orthogonal to each other and arranged in the horizontal direction or the vertical direction of the camera. Since the optical path splitting optical element is formed of a plurality of triangular prisms, the triangular prisms can be easily formed or integrated as in the invention of claim 5 or 6. According to the invention described in claim 7, the reflecting surface of the optical path splitting optical element is formed by four flat plate-shaped mirrors, so that the reflecting surface can be easily formed. According to the invention described in claim 8, since the reflecting surface of the optical path splitting optical element is formed by four flat plate-shaped mirrors, each mirror can be provided with an angle adjusting mechanism, which enables highly accurate adjustment. became. According to the tenth aspect of the present invention, since the reflecting surface of the optical path splitting optical element is fixed to the same member as the image pickup element, the positional relationship between the reflecting surface and the image pickup element can be set in advance with high accuracy. . The invention according to claim 11 is the image pickup apparatus according to claim 7, wherein the mirror is a half mirror and a subject image transmitted through the half mirror can be observed as an erect real image behind the half mirror. Since the system is provided, high-quality imaging is possible while observing the subject with the finder optical system.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of an image pickup apparatus of the present invention.

FIG. 2 is a diagram showing a state of light rays in a zoom lens camera to which the first embodiment is applied.

FIG. 3 is a perspective view showing a second embodiment of the imaging apparatus of the present invention.

FIG. 4 is a perspective view showing an example of a mirror angle adjusting mechanism in the second embodiment of the image pickup apparatus of the present invention.

FIG. 5 is a diagram showing a third embodiment of the image pickup apparatus of the present invention.

FIG. 6 is a diagram showing a fourth embodiment of the image pickup apparatus of the present invention.

[Explanation of symbols]

 11 1st split screen 12 2nd split screen 13 3rd split screen 14 4th split screen 20 Optical path splitting optical element 21 Triangular prism 21a 1st reflective surface 22 Triangular prism 22a 2nd reflective surface 23 Triangular prism 23a 3rd reflective surface 24 Triangular prism 24a Fourth reflecting surface 21 First reflecting surface 22 Second reflecting surface 23 Third reflecting surface 24 Third reflecting surface 31 First CCD image sensor 32 Second CCD image sensor 33 Third CCD image sensor 34 Fourth CCD image sensor 212 First Mirror 411 Eccentric screw 412 Eccentric screw 213 First mirror 313 First CCD image sensor 511 Frame 214 First mirror 234 Third mirror 314 First CCD image sensor 334 Third mirror

Claims (11)

[Claims] 1. An optical path splitting optical element for reflecting a light flux transmitted through an imaging lens on a reflecting surface to split the light flux into a plurality of light fluxes, and forming different portions of a subject image by the respective split light fluxes, and each of the split light fluxes. An image pickup apparatus comprising: a plurality of image pickup elements for receiving light; wherein the reflecting surface of the optical path splitting optical element is formed by each slanted surface of a plurality of triangular prisms. 2. The optical path splitting optical element according to claim 1, wherein there are four reflecting surfaces, and each reflecting surface is formed by four inclined surfaces of right-angled isosceles triangular prisms. Imaging device. 3. The light flux split by the optical path splitting optical element according to claim 1 or 2 forms one of the split subject images obtained by quartering the entire subject image formed when not split. The image pickup device is characterized in that the number of the image pickup elements is four, and the all-subject image is formed by synthesizing divided subject images formed by light beams received by the four image pickup elements. 4. The triangular prism according to claim 1, wherein each of the triangular prisms is arranged so as to reflect the subject light flux in a direction orthogonal to the optical axis of the photographing lens and in the horizontal or vertical direction. A characteristic imaging device. 5. The image pickup device according to claim 1, wherein the triangular prisms are integrally formed on the same substrate. 6. The image pickup device according to claim 1, wherein the triangular prisms are formed independently and are fixed on the same substrate. 7. An optical path splitting optical element for reflecting a light flux transmitted through an imaging lens on a reflecting surface and splitting the light flux into four directions, and forming different parts of a subject image by the respective split light fluxes, and each of the split light fluxes. An image pickup apparatus, comprising: four image pickup elements for receiving light, wherein the reflecting surface of the optical path splitting optical element is formed by four flat plate-shaped mirrors. 8. The image pickup device according to claim 7, wherein each of the mirrors includes an angle adjusting mechanism. 9. The angle adjusting mechanism according to claim 8, wherein the angle adjusting mechanism is an eccentric screw that supports the mirror with an eccentric shaft.
An imaging device characterized by. 10. The image pickup apparatus according to claim 7, wherein the mirror and the image pickup element are fixed to the same frame. 11. The finder optical system according to claim 7, wherein the mirror is a half mirror, and a rear part of the half mirror is provided with a viewfinder optical system for observing a subject image transmitted through the half mirror as an erect real image. A characteristic imaging device.